The present invention relates to a mounting bracket for attaching an aerodynamic fairing to a truck having cab roof contour edges disposed adjacent the edges of the aerodynamic fairing. More particularly, the mounting bracket includes an angled base plate which is mounted to the cab roof while accommodating the contour thereof and a deflector engaging face attached to the base plate for engagement of an interior surface of the aerodynamic fairing adjacent the roof, the lower end of the face including an outwardly extending tab thereon which engages the lower edge of the fairing to control the gap between the fairing and the cab roof. The tab further serves as a position indicator to permit the drilling of mounting bolt holes in the fairing from the exterior side which are properly positioned so that the mounting bolts will engage the otherwise blind holes disposed in the mounting bracket on the interior side of the fairing.